Valve or pump joint

ABSTRACT

A valve or pump gasket for sealing a fluid dispenser device comprising a valve or a pump mounted on a fluid container, said gasket being characterized in that it comprises one or more of the following elastomer materials: 
     a) a hydrogenated nitrile butadiene rubber (HNBR); 
     b) an octene-ethylene copolymer (OEC); and 
     c) a butyl or a halobutyl rubber.

The present invention relates to a valve or pump gasket for sealing afluid dispenser device comprising a valve or a pump mounted on a fluidcontainer.

More particularly, the gaskets of the invention are suitable for beingused both in dispenser devices for dispensing pressurized fluid andincluding valves, and in particular metering valves, and also indispenser devices for dispensing non-pressurized fluid and includingpumps.

The gaskets used in pressurized fluid dispensers, such as aerosoldevices must satisfy certain conditions and requirements. Thus, suchgaskets must offer good mechanical properties, and good resistance tomoisture, and must not swell too much when in contact with thepropellants. In particular, such characteristics are especiallyimportant for dynamic gaskets that provide sealing between the movingvalve member of the valve and the valve chamber that contains themetered quantity to be expelled.

For various reasons, and in particular for ecological reasons,chlorofluorocarbon (CFC) type propellants have largely been replaced byhydrofluoro-carbon (HFC) propellants of the HFC-134a or HFC-227 types,with or without alcohol. The use of such propellants, in particular whenthey are used with about 20% by weight of ethanol being added, increasesthe stresses on the gaskets, so that the conventional materials thatwere used in association with CFC gases no longer present optimumcharacteristics.

In addition, the gaskets used in non-pressurized fluid dispenserdevices, and in particular pumps, must also satisfy certain conditionsand requirements. Thus, such gaskets must offer good resistance tosolutions, in particular to water and ethanol solutions, i.e. solutionscontaining water, ethanol, or a mixture of water and of ethanol.Furthermore, such gaskets must offer good resistance to moisture andgood resistance to preservative agents, such as quaternary ammoniumcompounds.

An object of the present invention is to provide valve or pump gasketsthat satisfy the above-mentioned requirements.

An object of the present invention is to provide a valve gasket that isdesigned to come into contact with a fluid and with a propellant of thehydrofluoroalkane (HFA) type, with or without alcohol, and thatguarantees good mechanical properties and/or low swelling and/or goodresistance to moisture.

Another object of the present invention is to provide a pump gasket thatoffers good resistance to water/ethanol solutions and/or good resistanceto moisture, and/or good resistance to preservative agents, such asquaternary ammonium compounds.

Yet another object of the present invention is to provide a valve orpump gasket that is simple and inexpensive to manufacture.

The present invention thus provides a valve or pump gasket for sealing afluid dispenser device comprising a valve or a pump mounted on a fluidcontainer, said gasket being characterized in that it comprises one ormore of the following elastomer materials:

a) a hydrogenated nitrile butadiene rubber (HNBR);

b) an octene-ethylene copolymer (OEC); and

c) a butyl or a halobutyl rubber.

Advantageously, said gasket further comprises one or more otheringredient(s) such as inorganic fillers and/or carbon black fillersand/or vulcanization agents and/or pigments and/or processing agentsand/or plasticizers.

The present invention further provides a pressurized fluid dispenserdevice comprising a valve provided with a moving valve member, saidvalve being mounted on a container containing both the fluid and also apropellant, with or without alcohol, the device having at least one neckgasket between the valve and the container, and a dynamic gasket throughwhich said valve member slides, at least one of said gaskets being madeaccording to the present invention.

Preferably, the propellant comprises a hydrofluoro-carbon (HFC) gas ofthe HFC-134a type or of the HFC-227 type.

The present invention further provides a non-pressurized fluid dispenserdevice comprising a pump mounted on a container containing the fluid andat least one gasket between the pump and the container, said gasket orat least one of said gaskets being made according to the invention.

In a first variant, the gasket comprises as a base polymer essentially ahydrogenated nitrile butadiene rubber (HNBR). This hydrogenated nitrileelastomer generally has the following chemical formula:

This product is commercially available, and is, in particular, sold byBayer or by Nippon Zeon.

Hitherto, this elastomer has never been used as a valve or pump gasket.

It has been observed that, as a valve gasket, when it is in contact witha fluid of the HFC-134a or HFC-227 types, with or without alcohol (e.g.ethanol), it presents excellent mechanical properties, so that it isparticularly suitable for being used as a dynamic gasket. Naturally, itcan also be used as a neck gasket in such an aerosol device forproviding sealing between the valve and the container containing thefluid and the propellant.

In second variant, the gasket may be made in the form of an alloycomprising HNBR and octene-ethylene copolymer (OEC). Adding polyocteneguarantees, in particular, that the gasket does not swell too much whenin contact with propellants of the HFC type, with or without alcohol.

Particularly favorable results have been obtained, in particular, with agasket material comprising about 20% by weight of HNBR and about 80% byweight of OEC. In this composition, the gasket is particularlyinexpensive and easy to manufacture.

In a third variant embodiment, the elastomer component of the gasket maybe an alloy of HNBR and of butyl (or halobutyl) rubber. Adding butyl orhalobutyl rubber procures gaskets that offer good resistance to moistureand that do not swell too much in HFC-type propellants, with or withoutalcohol. Advantageous results have been obtained, in particular, with agasket material comprising about 60% by weight of HNBR and about 40% byweight of butyl or of halobutyl rubber.

In a fourth variant, the elastomer component of the gasket may be analloy of HNBR and of ethylene propylene (EP), or an alloy of HNBR and ofethylene-propylene-diene-monomer (EPDM). This type of alloy makes itpossible to obtain gaskets that swell little, in particular withpropellants of the HFC type, with or without alcohol, while alsomaintaining good mechanical properties. Favorable results have beenobtained at reasonable manufacturing costs in particular with gasketscomprising about 50% by weight or more of HNBR and about 50% by weightor less of EP or of EPDM.

In other variants, the elastomer component may also be an alloy of HNBRand of poly-chloroprene rubber (CR) or an alloy of HNBR and of styrenebutadiene rubber (SBR). These two types of alloy make it possible toobtain gaskets that have good mechanical properties and that do notswell too much in propellants of the HFC type, with or without alcohol.

HNBR is an elastomer component that is very advantageous in that itprocures good mechanical properties. However, it is possible to considermaking gaskets in which the elastomer component is octene-ethylenecopolymer (OEC). In particular when its elastomer component comprisesoctene-ethylene copolymer alone, this type of gasket offers goodmechanical properties and does not swell too much when in contact withpropellants of the HFC type, with or without alcohol.

Furthermore, it is also possible to consider making gaskets in which theelastomer component comprises butyl or halobutyl rubber. In particularwhen its elastomer component comprises butyl or halobutyl rubber alone,this type of gasket offers good resistance to moisture and does notswell too much in propellants of the HFC type, with or without alcohol.

All of the above-described gasket materials may further comprise one ormore other ingredients that are generally well-known in the field ofgaskets. In particular, the gasket formulations may further compriseinorganic fillers or carbon black fillers, vulcanization agents,pigments, processing agents, or plasticizers.

The valve gaskets of the invention for aerosol devices may therefore beused in a large number of applications, their formulations dependingmainly on the particular mechanical and sealing requirements as well ason the fluids and the propellants to be put in contact with saidgaskets.

Another feature of the invention is that the gaskets of the presentinvention are also applicable to non-pressurized fluid dispensersincluding pumps mounted on containers. In which case, the gasket(s)providing the sealing between the pump and the container may be made ofone of the above-described materials, thereby making it possible toobtain good resistance to water/ethanol solutions, good resistance tomoisture as well as good resistance to preservatives in particular toquaternary ammonium compounds. These properties are particularlyadvantageous in gasket formulations including HNBR, either alone or inan alloy.

Ease of manufacture and low cost are also advantageous features of thegaskets of the present invention.

Although particular composition ratios have been described above withreference to various gasket formulation variants, the present inventionis not limited to these ratios, and the scope of the patent is definedby the accompanying claims.

What is claimed is:
 1. A pressurized fluid dispenser device comprising avalve provided with a moving valve member, said valve being mounted on acontainer containing the fluid and a propellant, the device having atleast one neck gasket between the valve and the container, and a dynamicgasket through which said valve member slides; and wherein thepropellant compromises a hydrofluorocarbon (HFC) gas of the HFC-134atype or of the HFC-227 type; and at least one of said gasketscompromises a hydrogenated nitrile butadiene rubber (HNBR).
 2. A deviceaccording to claim 1, in which said gasket comprises an alloy of HNBRand of octene-ethylene copolymer (OEC).
 3. A device according to claim2, in which the gasket comprises about 20% by weight of HNBR and about80% by weight of OEC.
 4. A device according to claim 1, in which saidgasket comprises an alloy of HNBR and of butyl or of halobutyl rubber.5. A device according to claim 4, in which said gasket comprises about60% by weight of HNBR and about 40% by weight of butyl or of halobutylrubber.
 6. A device according to claim 1, in which said gasket comprisesan alloy of HNBR and of ethylene propylene (EP) or ofethylene-propylene-diene-monomer (EPDM).
 7. A device according to claim6, in which said gasket comprises about 50% by weight or less of EP orof EPDM.
 8. A device according to claim 1, in which said gasketcomprises an alloy of HNBR and of poly-chloroprene rubber (CR).
 9. Adevice according to claim 1, in which said gasket comprises an alloy ofHNBR and of styrene butadiene rubber (SBR).
 10. The device according toclaim 1, wherein the propellant includes alcohol.
 11. The deviceaccording to claim 1, wherein the propellant does not include alcohol.12. A device according to claim 1, in which said gasket furthercomprises one or more of the ingredients: inorganic fillers, carbonblack fillers, vulcanization agents, pigments, processing agents, andplasticizers.
 13. A device according to claim 1, in which said gasketfurther comprises one or more other ingredient(s) such as inorganicsfillers and/or carbon black fillers and/or vulcanization agents and/orprocessing agents and/or plasticizers.